Starting simple switch on 'DAHDI/8-1' then long pause

Hello, recently put in a

When a call comes in the message "Starting simple switch on ‘DAHDI/8-1’ " comes up in but the phone does ring. A full 9 or 10 seconds goes by then the following is in the log and the SIP phone starts to ring.

– Executing [s@from-pstn:1] NoOp(“DAHDI/8-1”, “Incomming call from PSTN: “” <>”) in new stack
– Executing [s@from-pstn:2] Dial(“DAHDI/8-1”,…

In chan_dahdi.conf I see the following:

; Specify whether the channel should be answered immediately or if the simple
; switch should provide dialtone, read digits, etc.
; Note: If immediate=yes the dialplan execution will always start at extension
; ‘s’ priority 1 regardless of the dialed number!

Is this causing this, what could it be doing for all of this time. What the heck is “simple switch”? I can’t find anything on the topic.

Thanks for any and all help,


Simple switch is irrelevant. You almost certainly have problems with your DNS configuration on the SIP side.

I still don’t know what “simple switch” is but we did get the long delay removed. It seems none of the pots lines have callerid on them. We added the usecallerid=no into the chan_dahdi.conf config and long delay was gone. I suspect the 10 seconds is a timeout waiting for the callerid information to come down the trunks… Whatever it is fixed.


Simple switch means that Asterisk is going to look for digits arriving on the line and try to invoked a dialplan extension as a result. It is normal for dahdi analogue lines.